Effects of high-pressure H${}_2$ and D${}_2$ post-metallization annealing on the electrical properties of HfO${}_2$/Si${}_{0.7}$Ge${}_{0.3}$

High-pressure annealing (HPA) in both hydrogen (H${}_2$) and deuterium (D${}_2$) environments is attempted on HfO${}_2$/Si${}_{0.7}$Ge${}_{0.3}$ capacitors as a post-metallization annealing (PMA) approach. As compared with conventional forming gas annealing (FGA), a dramatic reduction in the interface state density (D${}_{it}$) is achieved after both H${}_2$- and D${}_2$-HPA processes at the equivalent temperature (300 °C) and time (30 min) by effectively passivating the Ge-induced dangling bonds at the interface region. Meanwhile, the stress-induced leakage current characteristics are only improved by the D${}_2$-HPA process, indicating that D-passivation is more resistant to external electrical stress than H-passivation. As the PMA temperature increases to 500 °C, both HPA further decreases the D${}_{it}$, but a significant increase is observed for FGA. In addition, the PMA temperature-dependent degradation of leakage current is less in HPA than in FGA. (© 2022 Wiley‐VCH GmbH)